Thread: SHOW ALL doesn't actually SHOW ALL
Folks, I've noticed that neither SHOW ALL nor SELECT ... FROM pg_settings shows the value of custom GUCs, even though SHOW will do so for any given one. For example: SHOW plperl.use_strict;plperl.use_strict -------------------true (1 row) SELECT * FROM pg_settings WHERE "name" = 'plperl.use_strict';name | setting | unit | category | short_desc | extra_desc |context | vartype | source | min_val | max_val ------+---------+------+----------+------------+------------+---------+---------+--------+---------+--------- (0 rows) Is this a bug? Cheers, David. -- David Fetter <david@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fetter@gmail.com Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate
David Fetter <david@fetter.org> writes:
> I've noticed that neither SHOW ALL nor SELECT ... FROM pg_settings
> shows the value of custom GUCs, even though SHOW will do so for any
> given one.
Yeah, that's intentional, because what the code is designed to do is
allow GUC values for a user-written module to be specified before the
user-written module has been loaded. It's expecting the user-written
code to come along and issue a DefineCustomXXXVariable call so that
it will know how (or whether) to display the variable.
This ties back into previous discussions about how using this facility
for random user-set values is an abuse, and we ought to instead provide
some way of explicitly declaring user variables.
regards, tom lane
On Wed, Aug 20, 2008 at 01:56:50PM -0400, Tom Lane wrote: > David Fetter <david@fetter.org> writes: > > I've noticed that neither SHOW ALL nor SELECT ... FROM pg_settings > > shows the value of custom GUCs, even though SHOW will do so for > > any given one. > > Yeah, that's intentional, because what the code is designed to do is > allow GUC values for a user-written module to be specified before > the user-written module has been loaded. It's expecting the > user-written code to come along and issue a DefineCustomXXXVariable > call so that it will know how (or whether) to display the variable. I'm not sure I understand why that's the right thing. I stumbled across it while trying to improve some SQL-only checks in DBI-Link, and since SHOW doesn't quite act like SELECT, it's causing some trouble. > This ties back into previous discussions about how using this > facility for random user-set values is an abuse, and we ought to > instead provide some way of explicitly declaring user variables. How about seeing what all of them are via SELECT? I guess I'm missing why pg_show_all_settings(), the function underlying the pg_settings view, is actually doing pg_show_settings_except_the_ones_you_actually_set() :P Cheers, David. > > regards, tom lane -- David Fetter <david@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fetter@gmail.com Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate